The device itself costs $79 and comes with 1 GB of free data. Additional data costs $14 per gigabyte. It never expires and carries over until you use it.

Here's where Karma differs from a conventional hotspot, though – it remains an unprotected network. Every time someone joins your hotspot, you get 100 MB of free data. That person signs in via his Facebook profile as a means to prevent people from gaming the system, and his connection is throttled in such a way to make sure that your internet speed is never affected. Your network guest gets 100 MB of his own free data that doesn't come out of your allotment.

It's what Karma calls "social bandwidth."

I took a fully-charged Karma hotspot to a busy Starbucks on Park Avenue for a few hours to see how it worked in the real world. The connection was completely solid and reliable, pulling down great speeds over its network. There wasn't a single thing I wanted to do that I couldn't. Streaming Netflix, downloading semi-large files, even a FaceTime conversation – all functioned as if I were connected to my home WiFi.

There was one minor hiccup in this field test, however. During the few hours I was working off the hotspot, no one else joined my network to earn me some free bandwidth. This isn't a knock against Karma at all, mind you. But if you're buying one thinking you can operate off of your free data kickbacks, you're in for a rude awakening. Those free bursts of 100 MB are a good reason to opt for a Karma, but they're not the reason.

Instead, go for one because you like speedy and reliable data connections. And also if you like to share.